Polarization of atomic radiative transitions in crossed electric and magnetic fields

Abstract

A density-matrix approach is under development for the investigation of the angular distribution and polarization of atomic radiative emissions in crossed quasi-static electric and magnetic fields. Particular interest has centered on applications to spectroscopic observations in the intense fields of the high-power light-ion inertial fusion device PBFA II at Sandia National Laboratories, and to magnetic field measurements in tokamak plasmas. Noteworthy features of our general density-matrix analysis include allowances for the mixing of both the bound and continuum field-free atomic eigenstates in an arbitrary arrangement of electric and magnetic fields, and for the possible coherent excitation of the nearly degenerate field-dependent atomic substates that produce the overlapping Stark-Zeeman components. The influence of directed collisional excitation may also be taken into account. From the angular-momentum selection rules, specific results have been obtained for observation of polarized radiative emissions in the direction of the magnetic field.